Persistent energy transfer in ZGO:Cr3+, Yb3+: a new strategy to design nano glass-ceramics featuring deep red and near infrared persistent luminescence. Issue 35 (28th August 2019)

• Record Type: Journal Article
• Authors: Castaing, Victor; Sontakke, Atul D.; Xu, Jian; J. Fernández-Carrión, Alberto; Genevois, Cécile; Tanabe, Setsuhisa; Allix, Mathieu; Viana, Bruno
• Is Part Of: Physical chemistry chemical physics. Volume 21:Issue 35(2019)
• Page Start: 19458
• Page End: 19468
• Publication Date: 2019-08-28
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c9cp02927c
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : ZnGa2 O4 :Cr 3+, Yb 3+ nanocrystals, elaborated via glass crystallisation, show strong deep red and near infrared persistent luminescence chargeable by red light. Abstract : ZnGa2 O4 :Cr 3+, owing to its persistent luminescence properties in the deep red range, is an exceptional material in view of foreseen in vivo imaging applications. In the present work, we report the elaboration process and detailed investigations of the optical properties of nano glass-ceramics composed of spinel ZnGa2 O4 :Cr 3+, Yb 3+ nanocrystals embedded in a transparent, silica rich, glass matrix. The as-prepared materials show good incorporation of the dopants in the crystallites leading in both Cr 3+ and Yb 3+ emissions. These emissions occur while exciting in the Cr 3+ bands, indicating an energy transfer process from Cr 3+ to Yb 3+ . Furthermore, excitation in the Yb 3+ band in the near-infrared (NIR) range suggests an interesting up-conversion process, which promotes the Cr 3+ emission. Persistent luminescence of both Cr 3+ and Yb 3+ doping ions can be activated by charging the Cr 3+ excitation bands, leading to persistent luminescence of zinc gallate nanocrystals in both first and second biological windows. The influence of Yb 3+ co-doping on persistent luminescence properties has been investigated by persistent luminescence decay profiles and thermoluminescence studies. Indeed, thermoluminescence glow curves of Yb 3+ exhibit similar shape to those of Cr 3+ but appear broader and shifted towards higher temperatures. This temperature shift may be explained by the temperature dependence of the involved energy transfer process.